P-650 - Assessing the impact of water stress on Neofusicoccum parvum in table grapes using proximal sensing technologies

Water stress is a major limiting factor in Mediterranean agroecosystems and can increase crop susceptibility to diseases, including Grapevine Trunk Diseases (GTDs) like Botryosphaeria Dieback, caused by Botryosphaeriaceae species. In Italy, the incidence of GTDs on table grape young plants and nursery material has increased in recent years, highlighting the need to better understand the relationship between abiotic stress and pathogen spread. This study aims to explore the influence of water stress on the development of infections caused by Neofusicoccum parvum, one of the most common species associated with Botryosphaeria Dieback. Vine cuttings cv. Italia grafted onto Ruggeri 140 rootstock were exposed to different irrigation regimes (20%, 50%, and 100% of crop evapotranspiration) and inoculated with N. parvum, both rootstock and shoot under controlled growth chamber conditions. Plant water stress was monitored using low-cost thermal (flir one pro) and multispectral (mapir) sensors. Necrotic lesions were measured to assess disease severity. Water-stressed vines (20% and 50%) developed significantly larger lesions than fully irrigated plants. Results indicate that water stress increases host susceptibility and infection severity. This study also highlights the potential of smart sensors for water stress detection and providing new insights into how irrigation levels affect pathogen behavior. Findings contribute to a better understanding of abiotic–biotic stress interactions and support improved irrigation strategies to mitigate N. parvum infections in viticulture.